Syonyk

K. It started yesterday - I went out to my car after work and it was dead. No big deal, got a jump start.

It died on the entrance to the highway. No good. Managed to get a jump, and kept the RPMs above 2k for the entire trip to the auto parts store by my house, where I took the battery in and discovered it was *toast* - dropped to 1-2v under load. Replaced battery. When I was driving it, it lacked some power, but generally drove fine.

Today, it started fine, got me to work fine, and I needed to run a computer somewhere. Died on me getting onto the highway (same damn ramp). It wouldn't start - I'd turn the key, hear the starter click, voltmeter would drop to 8V or so, and not enough power to turn things over.

It finally got back enough juice to start, and I was able to get it back to my office. Unfortunately, this time, it had *no* power - idle below 1000 RPM is very lumpy, and it took slipping the clutch at 3000 RPM to get me going, wide open throttle at 4k RPM kept me at 30mph or so. Not good. Not good at all. The exhaust at idle is very "pulsing" and there's clearly a lot of fuel getting sent out the exhaust - the afterburning was just horrid while I was driving. It gets smooth over 2000 RPM, but still has no power.

I came back, pulled the plugs, and found the rear leading plug was fouled. I replaced all 4 plugs.

Still the same thing - terrible idle, no power at all. It's also hesitating when I stomp on the throttle - it dies for a second, then begins winding up slowly.

I suspected the leading coil wasn't firing well, so I tried starting it on the trailing plugs only. It ran, but not quite as well. Also, the leading coils arc with the wire disconnected, so they're at least generating something.

I also tried regrounding the engine with a set of jumper cables, from a bolt on the engine to the frame. It didn't help, and the existing grounding wire still looks fine (I know it sucks, but that's a problem for a later date).

I haven't checked compression, but from my understanding, an engine with a blown apex seal still runs once the RPMs get up - and still has some amount of power. Mine has no power.

I tried running it on the leading & trailing plugs - it runs on both, so apparently both are at least firing. However, it's pretty clear that not a lot of gas is burning based on the exhaust smell.

I also tried resetting the ECU by cutting power & hitting the brake pedal a few times, no joy.

Voltages as measured at battery terminals:
12.7v battery voltage when stopped, 14.1v when running.

Ideas? I'm probably going to take it to a local repair shop later tonight or tomorrow morning. I'm hoping it's not a blown apex seal, because I flat out don't have the time/money/skills/equipment to rebuild an engine right now. And it was my daily driver. :-(

-=Russ=-

WAYNE88N/A

It sounds like you had 2 problems, but then at the end there you said you had 14v with the alternator spooling, so that begs another question- why did the battery die in the first place? Was it just old?

If I were you, the first thing I would do is a compression check- do a search, there's gotta be 1000 threads on the subject...Gotta make sure it's not the engine first before we go through further troubleshooting...

Syonyk

Yea, battery was 2001-era, and not secured down - so it was probably bouncing around.

And, I just did a "Thumb/ear compression test"

Front rotor: "Chuff Chuff Chuff"
Rear rotor: "... ... ..pip"

*sigh* Rebuild time, 120k miles. While I was using it as a daily driver. Any good rebuild shops or people in Milwaukee?

-=Russ=-

trainwreck517

iTrader: (1)

rear rotor might be flooded, poor a bit if atf and see if that helps.

WAYNE88N/A

Sorry to hear that, man, welcome to the wonderful world of rx-7's!...If it makes ya feel any better, I had a blast rebuilding mine...

J-Rat

iTrader: (2)

FYI, The 88 ECU doesnt store codes... As soon as you turn off the ignition, it dumps everything... ITs a "dumb ECU"

Rat

WAYNE88N/A

I thought I read somewhere that the ECU "learns" parameters during long periods, kinda like it'll start adjusting things to make up for an engine getting tired or something like that, and it'll keep the last "parameters" it used on the next startup...Am I just smoking something, or what???

J-Rat

iTrader: (2)

Your smoking alot of something..
The S4 ECU doesnt generate MAPS, doesnt LEARN and definately doesnt STORE anything.

It uses an algorithm to determine pulsewidth (read DUTY CYCLE before HAILERS and NZconvert jump my case). Its a dumb computer...

WAYNE88N/A

Gotcha...

Syonyk

I'd imagine if it was flooded, running a while & such would fix it. From the time it died, there was no change in condition in running/power/etc until I tested the compression - so unless the rear rotor flooded out & several (8-10) minutes of running didn't fix it, I'm guessing it's something more.

The car's flooded on occasion, I just turn off the fuel pump, crank till it starts, and turn the pump back on - it's fine. Is it really possible for one rotor to remain flooded through a series of restarts/running/etc, including several times of "shut off fuel pump, crank engine till it starts & burns off fuel & shuts down"?

-=Russ=-

trainwreck517

iTrader: (1)

Eh, I guess its not flooded, a rotor should unflood after a min or so of running expecialy if it was reved up too about 5-7k.

WAYNE88N/A

Only if ya got huge injectors on there that are drowning the engine, but I don't think that's the prob, right? Could it be possible you got an injector so gunked up that it "sticks" open?

Russ

how are your battery terminals? i had the same problem. replaced my terminals and havent had a problem since.

Syonyk

Oh, it was a blast to drive for all 3 months I had it. :-) Needs new brakes though.

Well, my options as I see them:

Purchase new engine, send in old core. $2000, plus shipping & installation (I don't have access to an engine hoist or anything - is it possible to install the engine without one?).
Advantages: Quick, fairly easy
Disadvantages: Expensive!

Take car somewhere, have engine rebuilt. $????
Advantages: Probably get the car back running fairly soon. Someone else who is hopefully skilled is doing the actual work.
Disadvantages: Someone else is working on my car & doing all the fun stuff. Probably still damned expensive.

Rebuild engine myself: $???
Advantages: I can learn to rebuild them, get experience, make sure everything is squeaky clean, etc. This would also be a wonderful way to fill the boredom that this summer is creating.
Disadvantages: I have no engine lift or such, I doubt I can rebuild the engine as quickly as someone who knows what they're doing,
and there's probably a decent chance of me screwing something up, and I really don't have anywhere to work.

Sell car for scrap, obtain something that runs: $2000+
Advantages: I would rapidly have a working car, possibly with 4 seats.
Disadvantages: I rather like my RX-7, I paid $2500 for it 3 months ago and could probably get $500 for it without a working engine, and I would no longer have a fun sports car to drive.

Suggestions? *sigh* My biggest question is what type of skill (and how long) it takes to rebuild a rotary. I have a decent set of sockets & such, but I'm a computer guy just starting to work on cars. I'm sure I could take the engine apart, but I'm not quite as sure I could get everything back together and working. I know the engines aren't terribly complex to rebuild, but I don't have a lot of money to throw at the problem, and if I try to rebuild it & fail, I'm at the same place as when I started, except without an engine core & a few weeks later.
The plus side is that I'm doing *nothing* this summer except working, so if I could find a place, I could easily amuse myself for a few weeks (hopefully less) with this task.

-=Russ=-

Syonyk

Negative terminal was junk, was replaced with a brand new one.

Positive terminal is beat up, but still looks decent enough to work, though it could be responsible for the low cranking voltage. It's on the list of things I was planning to replace in the near future.

I'm honestly more concerned about the lack of compression on the rear rotor. What would cause that? It's not a "Chuff ... ..." that would indicate a blown apex seal (As I understand it), but basically no signs of compression except for a tiny spurt of air.

-=Russ=-

WAYNE88N/A

Keep the rex!!! Engine chain hoists can be had for $40- that's what I used...used a piece of plywood & 2 by 4's to put the engine on while rebuilding. Bought the flywheel nut tool & flywheel stopper from Mazdatrix, $55 or so. Hung the chain hoist from a 4 by 4 frame assy that's part of the garage. Rebuild kit & video from Rotary Aviation, $870 & $30, respectively. New rotor housings, $1000 (I had 186,000 on the old ones, you could probably skip that step). Studied the Haynes & FSM for a while. Only problems I had were the stiff-*** RA combustion o-ring popping out on me from the groove while putting the housing together (discovered it after I torqued everything down), and an engine equalizer would have made life a little easier (took the engine/tranny out as a unit, had to put a hell of an angle on it to clear the front)...600+ miles on it now, runs kick-***...

Syonyk

How long would it take a complete idiot to rebuild the engine?

I have a car I can borrow for the next week. Unfortunately, while I can bike to my job, I have to go visit clients & such, which requires rapid transportation, often hauling computers & such. So, really, I need my car back operational within 2 weeks or less. It looks like rebuild kits take a week or so to ship. What's the time for a rebuilt engine to arrive, usually? Also, how difficult is it to get the engine in/out of the car? If I were to take it somewhere to have the engine swapped, how much would it likely run me? Right now I have a bike to get around, and zero people I know in the area with anything to help rebuild an engine.

-=Russ=-

darkracer21

Im in the same position you are in right now. I dont really have the money for a rebuild right now. Is there anyway you could ride public transportation for work while your car is down.

Syonyk

No. Getting to work isn't the problem - I can bike it if needed. Getting from work to the clients we support is the problem. I can borrow vehicles and such and get 2-3 weeks of vehicle use, hopefully. I still need to find a solution very, very soon.

-=Russ=-

tie pilot

not to overlook the easy stuff: have you had you NEW battery load-tested?

just b/c it's new doesn't mean it's good.

EDIT: it hapened to me once

Syonyk

No, I was actually planning to do that, but then the car died on me. I don't think the battery will cause crap running & zero compression though. :-)

-=Russ=-

Syonyk

Double post.

pip

Yes?

If you plan on doing the rebuild yourself ill be glad to give you a hand and I might even let you borrow my copy of overhauling the 13b on vhs, but thats only if you ask real nice

Syonyk

Nice. Where in Milwaukee are you, and do you have access to an engine lift? If I can get the engine out, I have a place I can work on it (my room, basically). Getting it in & out, and keeping the car somewhere while I'm working on it - that's the trick. Drop me an email or PM or such, if you wouldn't mind. :-)

-=Russ=-

pip

Between me and cooper (both around calhoun and capitol in brookfield) we have just about everything you need to do the rebuild. Do you already have a rebuild kit? If not coopers got a hurley rebuild kit with new side seals, apex seals, and just about every gasket you would need. Hit me with a pm if you want.